Author: Landon Rabern
Date: 20:13:13 12/08/00
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On December 08, 2000 at 22:22:24, Robert Hyatt wrote: >On December 08, 2000 at 20:41:40, Landon Rabern wrote: > >>On December 08, 2000 at 16:16:01, Robert Hyatt wrote: >> >>>On December 08, 2000 at 13:21:21, Peter Fendrich wrote: >>> >>>>On December 08, 2000 at 13:06:43, Robert Hyatt wrote: >>>> >>>>>On December 08, 2000 at 12:56:09, Peter Fendrich wrote: >>>>> >>>>>>I looking for a measurement for move generation performance. >>>>>> >>>>>>Do you think FH/CountNodes, where FH is number of times the first generated move >>>>>>was a Fail High, is a good measurement? >>>>>>Do you have some other? >>>>>>What's your figures? >>>>>>I get some 50% and I have a feeling it's to low. >>>>>> >>>>>>//Peter >>>>> >>>>> >>>>>The critical statistic I measure in crafty is this: "For any position where >>>>>I 'fail high' (return a score >= beta) what percentage of the time does it >>>>>happen on the _first_ move?" I generally average 92%. Anything over 90% is >>>>>reasonable. Anything less means move ordering needs work. >>>> >>>>OK, it seems logical. I have in princple 3 types of FH: >>>> 1) Hash table (without moving) >>>> 2) Null Move >>>> 3) Ordinary moves (including the hash table move) >>>> >>>>Do you include all these cases? >>>>With only the third case counted I'm well over 90% >>>> >>>>//Peter >>> >>> >>>Only 1 and 3. 2 is done at a different place in the search and doesn't >>>really count in "move ordering". >>> >>>Actually, the way you wrote it, only 3 counts. for 1) you are not searching >>>a move, so that can't be counted. 2) doesn't count either... >> >>I am getting about 80% on this, is this real bad? I am not doing internal >>interative deepening, do you think this will help a lot, or do you think there >>is something else wrong. >> >>I try moves in this order: >> >>hash/pv >>all captures sorted MVV/LVA >>two killers >>3 history scan moves >>the rest >> >> >>Regards, >> >>Landon W. Rabern > > >Your MVV/LVA ordering is probably the culprit. Because you are trying moves >like QxP, even though the pawn is defended... and you try those _before_ you >try the move that will ultimately fail high (a killer or history move). > >I would still expect it to be higher than 80%... but that might be about right >with MVV/LVA. You get some of that back in terms of faster ordering, and you >get some back because the bad captures get cut off quickly by null-move >searches... but it could be better... Ok, I switched to using my SEE to order the moves, but did not do the bad captures last yet(no time yet), just did them all at once, but ordered with SEE. Now I get about 86%-89%. Do you think I should be able to get over 90% by doing bad captures last? Regards, Landon W. Rabern
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